English▸ noun [mass noun]
1 great enthusiasm and energy:
they campaigned with zest and intelligence
[in singular] she had a great zest for life.
▪ a quality of excitement and piquancy:
I used to try to beat past records to add zest to my monotonous job.
2 the outer coloured part of the peel of citrus fruit, used as flavouring:
add 3 tablespoons of lemon zest.
▸ verb [with object] scrape off the outer coloured part of the peel of (a piece of citrus fruit) for use as flavouring:
zest the orange and lemon, taking care to discard all of the white pith.
– ORIGIN late 17th century (in sense zest (sense 2 of the noun)): from French zeste ‘orange or lemon peel’, from obsolete zec ‘membrane around walnut kernel’, ‘object of no importance’.